When a body of an aircraft is damaged, it is important to detect the damage promptly. Therefore, various arts for detecting damage arising in a body of an aircraft are proposed (For example, refer to Japanese Patent Application Publication JP2011-194974 A and Japanese Patent Application Publication JP2008-536756 A). For example, technique for detecting damage by detecting an ultrasonic wave with a sensor disposed on a structural object composing an aircraft is proposed.
Although the conventional damage detection arts are suitable for an aircraft examination on the ground, they are difficult to detect damage with high accuracy during a flight. This is because strains arise in structural objects composing an aircraft due to factors including movements and vibrations of the aircraft body in addition to damage during a flight of the aircraft.
Accordingly, an object of the present invention is to make it possible to detect damage of an aircraft during a flight with higher accuracy.